Improvement in screw-cutting machines



G. EMIS.

Screw Cutting Machines.

Paienfedlan. 14,1873.

No. when.V

lIllvelmto1? collars J J' and J'l J'.

UNITED STATES PATENT OFFICE.

GEORGE EMIG, OF CINCINNATI, OHIO.

IMPROVEMENT IN SCREW-CUTTING MACHINES.

Specification forming part of Letters Patent No. 134,871, dated January14, 1873.

Nature and Objects of Invention.

My invention consists of certain devices by which the machine isadjusted in a peculiar manner to cut automatically threads of anydesired length upon thebolt; and also consists of a peculiar devicedesignedl to enable the operator to conveniently adjust the bolt in thejaws of the chuck which secures it.

Description of the Accompanying Drawing,

Figure 1 is a perspective view of a machine embodying `my invent1on.Fig. 2 is a plan of the same.

General Description.

A is the frame of the machine; B, the spindie; and C, the die-chuck.erated automatically by levers D D', sliding cone E, and spring F. Thecone swivels in the cross-bar G, to which it is confined laterally bymeans of a groove in the cone, into which the bar G its. The outer endsof the bar G are firmly secured, by set-screws, locknuts, or otherwise,to the sliding bars or rods H H', which are supported on brackets I I.The bars or rods H H' have adjustable collars J J' J" J' secured to themby set-screws j.

lThe sliding bolt-chuck K has an ear on each side firmly attached to it,marked L L' in the drawing. These ears surround the bars H H' in themanner shown in positions between the The bars H H' are graduated, inparts of an inch and inches, in the manner shown, so that the collarscan be adjusted accurately to define the points at which the dies areopened and closed, and the length of the screw thus determined, thecollars being the means of governing the length of motion ofthebolt-chuck. When the ears L L' strike the collars in either directionthe dies are thereby opened and closed.

In cutting bolts the bolt-chuck has to be moved back after the cuttingof each bolt a sufficient distance to enable the dies to close after thebolt has beenwithdrawn therefrom,

and therefore the end of the next bolt has to' Abe the saine distancefrom the face of the diechuck when it is secured for cutting.

To facilitate the accurate adjustment of the The dies are op-n boltpreparatory to its being forced into the dies I have provided thefollowing device: An adjustable gage, M, having an aperture, on, throughwhich the bolt passes in being cut, is-secured to the frame A, byset-screwor bolt N, in such a way that it can be moved in eitherdirection to effect the desired adjustment, the end which is perforated(marked m) being a sufficient guide to enable the operator to locate theend ofthe bolt, in the operation of securing it, in the chuck whichholds it.

It will be seen that, by the provisionof the two side rods H H',cross-bar G, two ears, L L', and collars J J' J" J', when the cone E ismoved to either open or close the dies, the strain upon it is perfectlybalanced, and but little power is required to move it, and but littlefriction attends the motion of any of the parts. This is a veryimportant matter when it is considered that it is the threads of thebolt itself which sustain the stra-iu in the automatic opening of thedies.

I am aware that heretofore screw cutting machines have been built inwhich the boltchuck has a single tappet-arm acting upon collars of aslide-rod connected to a sliding cone in such a manner as toautomatically open the dies the moment the desired length of thread iscut. I do not, therefore, claim this feature broadly, but confinemyselfto sin h a duplication of said mechanism as will relieve thethreads of the bolt of undue and unequal strain during the action ofopening the dies, as hereinbefore explained.

Claims.

l. The bolt-chuck K, having two tappetarms, L and L', and the slidingcone E, in combination with the bar or cross-head G and a pair ofgraduated slide-rods, H and H', which are provided, respectively, withadjustable collars J J' and J" J', all substantiallyr as and for thepurpose specified.

2. rIhe adjustable gage M nz, iu combination with the bolt-chuck K anddie-chuck O, the dies of which are opened and closed automatically bythe bolt-chuck through intermediate mechanism, substantially as and forthe purpose specified.

In testimony of which invention I hereunto set my hand.

GEORGE EMIG.

Witnesses FRANK MILLWARD, J. L. WARTMANN.

